Online tool to check server HTTP/2, ALPN, and Server-push support.

HTTP/2, ALPN, NPN and Server-push support analyzer

Human

I'm Ayesh Karunaratne, a web developer based in Sri Lanka (technically), but hardly
stays in the country (practically) because I love traveling solo, and can't get enough Nasi Lemak in Sri Lanka. You
can contact me if you have any queries.

Bot

HTTP2.Pro is an online tool to quickly check the HTTP/2 support of any web site, or your own browser.

For the server test, this tool sends an HTTP HEAD request with an option for the server to opt
to use an upgraded protocol.

For the client test, the web page makes the browser send a few request, and uses Javascript to calculate the time
it takes to download the images over both HTTP/1.1 and HTTP/2. To improve the sampling size, several requests
are made.

If you are interested in checking client HTTP/2 support over an API, we have a
minimal API available.

Our bot identifies itself as Http2Bot vX.Y.Z (https://http2.pro/about?bot_v=X.Y.Z). If you are seeing
HEAD requests being made to your server, it is probably from this tool. To minimize applification
attacks and other possibile abuses, this tool strictly makes HEAD requests, and only to the base domain name
checked against. Currently, there is no support for robots.txt standard, but feel free
to contact me if you would like to opt-out. However, this tool does
not allow any programmed requests for the server HTTP/2 check, and all pages are secured against CSRF attack as
an effort to keep the impact on your site from the bot minimal.